Auxiliary Cab Cooling Compressor on a Shared AC Refrigeration Loop

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Solution Overview

Problem

Conventional vehicle cab air conditioning systems require a separate refrigeration loop when the vehicle engine is not running, leading to duplication of components and increased complexity.

Innovation Solution

An auxiliary compressor system powered by a service engine, connected to the vehicle's air conditioning refrigeration loop, which includes a controller to manage loads and activate the auxiliary compressor when the vehicle engine is off, eliminating the need for a separate refrigeration loop and allowing the service engine to drive various other loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a separate refrigeration loop is used when the vehicle engine is not running, then cab cooling is provided, but component duplication and system complexity increase

Engineering Contradiction:

Improvecab coolingVSAvoidrefrigeration loop complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the auxiliary refrigeration system with the vehicle's existing refrigeration loop by integrating a condenser that dissipates heat into the vehicle's radiator. This allows the auxiliary compressor to operate using the vehicle's shared refrigeration infrastructure rather than requiring a completely separate system, thereby reducing component duplication while maintaining the ability to cool the cab when the engine is off.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The auxiliary condenser is designed to serve multiple functions: it acts as a heat dissipation device for the auxiliary compressor during engine-off cooling, and simultaneously functions as part of the vehicle's overall thermal management system by integrating with the radiator. This multi-functionality reduces the need for dedicated separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Temperature

If the service engine drives the auxiliary compressor, then cab cooling is achieved without the vehicle engine, but the service engine must manage additional power loads

Engineering Contradiction:

Improvecab coolingVSAvoidservice engine power capacity

Core Design Contradiction:

TemperatureVSPower

Solution Approach 1:

The system dynamically manages the service engine's power output based on operational conditions. The controller monitors the engine's power availability and adjusts the auxiliary compressor's operation accordingly, allowing the system to adapt to varying power demands and optimize the balance between cooling requirements and other power loads.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller adjusts operational parameters such as compressor speed and refrigerant flow rates to optimize system performance under different power availability conditions. By changing these parameters dynamically, the system can provide adequate cooling while managing the service engine's power capacity constraints.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the auxiliary compressor is integrated into the vehicle's refrigeration loop, then component duplication is reduced, but the system requires coordinated control between vehicle and auxiliary systems

Engineering Contradiction:

Improvecomponent duplicationVSAvoidcontrol coordination

Core Design Contradiction:

Device complexityVSExtent of automation

Solution Approach 1:

The controller receives feedback signals from various sensors monitoring refrigerant pressure, temperature, and system operational status. This feedback mechanism enables the controller to automatically adjust the auxiliary compressor's operation and coordinate with the vehicle's refrigeration system, managing the complexity of integrated control through automated response to system conditions.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution provides efficient cab cooling without relying on the vehicle engine, reduces component duplication, and allows the service engine to power additional loads, optimizing energy use and system efficiency.

Implementation Method 1

an auxiliary compressor to selectively pump refrigerant fluid through a cooling system of the vehicle

Methodology Applied

Scientific EffectVapor compression refrigeration:

Implementation Method 2

the auxiliary compressor to selectively pump refrigerant fluid through a coolant loop of a cooling system integrated within a vehicle

Methodology Applied

Scientific EffectHeat transfer:

Data Source

PatentUS11993155B2Auxiliary power unit air conditioning for truck cab cooling

Publication Date: 2024.05.28 ILLINOIS TOOL WORKS INC

AI summary

Systems are disclosed for providing a work vehicle with a second air conditioning compressor driven by a small engine mounted on the work vehicle. The second compressor shares a refrigeration loop with the primary air conditioning compressor of the work vehicle. The small engine may be configured to drive various loads, and accordingly may include control circuitry to manage the power provided to the various loads, including the second compressor.